Alcohol, training and recovery: What the data really says

Most runners know a big night out can sabotage a bit session, but the science on alcohol and performance is now impossible to ignore. 

In this article, performance dietitian Cushla Holdaway (MSc Sports & Exercise Nutrition) - who works with elite endurance athletes across New Zealand and beyond - unpacks why more athletes are turning away from alcohol, what the latest health and sleep data shows, and how evern 'just a few' drinks can quietly undermine your recovery, adaptation and long-term health.

Cushla writes:

I used to occasionally drink alcohol, but then I realised the drinks I most enjoyed were alcohol-free, and secondly, I found it hard to ignore the unequivocal evidence illustrating the deleterious impacts of alcohol on our health and society. 

I am a proud non-drinker, and recent evidence has shown I’m not alone, with a 12% decline in the consumption of beer, wine, and spirits in New Zealand between 2023 and 2024 (1).

The New Zealand health survey data further supports this, with significant declines specifically in the 25-34 and 35-44 age groups between 2014 and 2020 (2). It is your choice as to what and how you drink, however, I think everyone should be able to make an informed choice. With summer events now in full swing, let’s look at some of the facts.

According to the World Health Organization (WHO), drinking alcohol (a class one carcinogen) is strongly linked to many noncommunicable diseases including liver disease, heart disease, and certain cancers, as well as numerous mental health and behavioural disorders.

Alcohol increases the risk of breast, liver, head, neck, esophageal and colorectal cancers, with approximately 4.4% of all cancers diagnosed globally in 2019 attributable to alcohol consumption alone. This doesn’t include the increased incidences of deaths due to falls, drownings, burns, violence, road accidents or violence where alcohol is involved (3). 

In terms of your recovery and sleep, it’s not good news I’m afraid. Oura rings science team recently analysed >600,000 members' data between January and September 2025 - with some stark results. On nights where Oura ring users tagged alcohol, average heart rate increased by 9.6%, average sleep duration reduced by 35 minutes, and heart rate variability (HRV) takes the biggest hit of all, with users experiencing ~16% drop after including alcohol (4).

Lower HRV impacts our parasympathetic system (think ‘rest & digest’), i.e. alcohol = more strain on the body.

A final point to consider is that pure isolated alcohol has 7 calories per 1g (approx. 1mL). A standard drink has about 10g pure alcohol, so even if you have gin with sparkling water, that’s still minimum 70cal per drink. Keep in mind a standard drink is about 330mL standard beer, 100mL wine, or 30mL of spirits. Low carb drinks on the market do not mean low/no calories. On a positive note, with the rise of more people wanting healthier options, there are now some reasonable options on the market that are alcohol free with low/no sugar.

References

1.     Stats NZ, Alcohol available for consumption year end June 2023 (8.742) and June 2024 (litres of alcohol per head of population), accessed 28^th November 2025: Browse – Infoshare – Statistics New Zealand (stats.govt.nz)

2.     Ministry of Health, Annual Data Explorer, published November 2025, accessed 28^th November: https://minhealthnz.shinyapps.io/nz-health-survey-2024-25-annual-data-explorer/_w_421dbfd34490476f9f2f0c0dc345b0b3/#!/explore-indicators

3.     World Health Organization, Fact sheets, Alcohol, published 28^th June 20204, accessed 28^th November 2025: https://www.who.int/news-room/fact-sheets/detail/alcohol

Oura Community “Oura Data Reveals the True Impact of Alcohol on Sleep, accessed Friday 28^th November 2025: https://ouraring.com/blog/how-does-alcohol-impact-oura-members/?lid=q1f3lh7n6gu3&utm_source=user&utm_medium=email&utm_campaign=2025Digest&utm_type=alwayson_ctr&utm_variant=20251124_NovemberDigest_Members_EM01_SLA&utm_content=blog_button_spot2&_brz=68fecaa2da8ca900586e262c